Off-road vehicles

Abstract

To improve the cooling performance of the radiator while preventing the vehicle from becoming larger. [Solution] The off-road vehicle comprises an internal combustion engine, a circulation passage through which coolant flows to cool the internal combustion engine, a first radiator located in the front space behind an outside air intake opening, interposed in the circulation passage, and including a first heat exchange core, and a second radiator located in the front space behind the first radiator, interposed in the circulation passage, and including a second heat exchange core. The first radiator is arranged such that the first heat exchange core overlaps the second heat exchange core from the front.

Description

Technical Field

[0001] The present disclosure relates to an off-road vehicle equipped with a radiator.

Background Art

[0002] Patent Document 1 discloses a utility vehicle equipped with a radiator. A utility vehicle can also be referred to as an off-road vehicle. This vehicle includes a radiator through which cooling water for cooling an internal combustion engine flows.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Increasing the size of the radiator to improve its cooling performance leads to an increase in the size of the vehicle.

[0005] Therefore, one aspect of the present disclosure aims to enhance the cooling performance of the radiator while preventing an increase in the size of the vehicle.

Means for Solving the Problems

[0006] An off-road vehicle according to one aspect of the present disclosure comprises: a cabin on which an occupant seat is arranged; a front cover covering a front space located in front of the cabin and including at least one outside air intake opening facing forward of the vehicle; an internal combustion engine; a circulation passage through which a coolant for cooling the internal combustion engine flows; a first radiator located in the front space behind the outside air intake opening, interposed in the circulation passage, and including a first heat exchange core; and a second radiator located in the front space behind the first radiator, interposed in the circulation passage, and including a second heat exchange core, wherein the first radiator is arranged such that the first heat exchange core overlaps the second heat exchange core from the front. [Effects of the Invention]

[0007] According to one aspect of this disclosure, it is possible to improve the cooling performance of the radiator while preventing the vehicle from becoming larger. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a left side view of an off-road vehicle according to an embodiment. [Figure 2] Figure 2 is a left side view of an off-road vehicle showing the internal combustion engine cooling system of Figure 1. [Figure 3] Figure 3 is a left side view of each radiator and its vicinity as shown in Figure 2. [Figure 4] Figure 4 is a perspective view of each radiator and shroud from the front left, as seen in Figure 3. [Figure 5] Figure 5A is a front view of the front of the off-road vehicle shown in Figure 1, seen from the front of the vehicle. Figure 5B is a front view of Figure 5A with the front upper cowl removed. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. In the following description, unless otherwise specified, directions are based on the direction of the off-road vehicle 1, with the vehicle's longitudinal direction corresponding to the vehicle's length direction and the vehicle's width direction corresponding to the vehicle's left-right direction.

[0010] Figure 1 is a left side view of an off-road vehicle 1 according to an embodiment. As shown in Figure 1, the off-road vehicle 1 comprises a body frame 2, a pair of left and right front wheels 3 supporting the front of the body frame 2, and a pair of left and right rear wheels 4 supporting the rear of the body frame 2. The tires of the front wheels 3 and rear wheels 4 may be, for example, balloon tires for off-road driving. The off-road vehicle 1 may also be called a utility vehicle.

[0011] The vehicle frame 2 is a pipe frame made up of multiple pipes connected to each other. The vehicle frame 2 includes a floor frame 2a, a cabin frame 2b, a seat support frame 2c, etc. The floor frame 2a supports the occupant seat 6 from below via the seat support frame 2c. The cabin frame 2b defines the cabin C where the occupant seat 6 is located.

[0012] In front of the cabin C, a front cover 5 is positioned, supported by the vehicle frame 2. The front cover 5 covers the front space S between the left and right front wheels 3 from above. The front cover 5 includes an outside air intake section 40 that opens the front space S toward the front of the vehicle and introduces outside air from the front of the vehicle into the front space S. The front space S contains the first radiator 21 and the second radiator 22 of the internal combustion engine cooling system 20, which will be described later. The first radiator 21 is positioned behind the outside air intake section 40. The second radiator 22 is positioned behind the first radiator 21.

[0013] Side doors 7, which open and close the entrances for passengers to enter and exit cabin C, are located on both sides of cabin C. The front space S and cabin C are separated by a dash panel 8. A dashboard 9 is located behind the dash panel 8 and in front of the passenger seat 6. The dashboard 9 faces the passenger seat 6 from the front. Instruments are installed on the dashboard 9. A handle 10 facing the passenger seat 6 is located on the dashboard 9. Electrical components and other items are housed in the space between the dash panel 8 and the dashboard 9.

[0014] Behind the cabin frame 2b is a cargo bed 11 that defines an upwardly open, concave loading space. Behind the crew seats 6 is an internal combustion engine 12 supported by the vehicle frame 2, which serves as the prime mover. At least a portion of the internal combustion engine 12 is positioned vertically below the cargo bed 11 in a side view of the vehicle.

[0015] A continuously variable transmission (CVT) 13 is adjacent to the internal combustion engine 12. The CVT 13 changes the rotational speed of the driving force output by the internal combustion engine 12. The driving force output from the CVT 13 is transmitted to one or both of the front wheels 3 and the rear wheels 4. Although the internal combustion engine 12 is used as the prime mover, a combination of an internal combustion engine and an electric motor may be used as the prime mover, or an electric motor alone may be used as the prime mover.

[0016] Figure 2 is a left side view of the off-road vehicle 1 showing the internal combustion engine cooling system 20 of Figure 1. As shown in Figure 2, the off-road vehicle 1 is equipped with the internal combustion engine cooling system 20. The internal combustion engine cooling system 20 comprises a circulation passage 30, a first radiator 21, a second radiator 22, a radiator fan 23, a coolant pump 24, a thermoswitch 25, and a power supply line 26.

[0017] The circulation passage 30 is a closed-loop passage through which coolant flows to cool the internal combustion engine 12. The circulation passage 30 includes a first radiator 21 and a second radiator 22 located in the front space S. The circulation passage 30 includes a first coolant passage 31 connecting the outlet of the cooling passage of the internal combustion engine 12 to the first radiator 21, a second coolant passage 32 connecting the first radiator 21 to the second radiator 22, and a third coolant passage 33 connecting the second radiator 22 to the inlet of the cooling passage of the internal combustion engine 12. The first coolant passage 31 is defined by a first coolant tube 41, the second coolant passage 32 is defined by a second coolant tube 42, and the third coolant passage 33 is defined by a third coolant tube 43.

[0018] The coolant pump 24 is located in the circulation passage 30. For example, the coolant pump 24 is located in the third coolant passage 33. The coolant pump 24 pumps coolant so that it flows in the following order: internal combustion engine 12, first coolant passage 31, first radiator 21, second coolant passage 32, second radiator 22, third coolant passage 33, and then back to the internal combustion engine 12. That is, since the first radiator 21 and the second radiator 22 are arranged in series in the circulation passage 30, the coolant flowing through the circulation passage 30 is cooled in stages by the first radiator 21 and the second radiator 22. The first radiator 21 is located upstream of the second radiator 22 in the circulation passage 30. As a result, the temperature difference between the air and the coolant is increased in the first radiator 21, effectively cooling the coolant, and the coolant is further cooled in the second radiator 22.

[0019] The radiator fan 23 is mounted on the second radiator 22, positioned adjacent to the rear of the second radiator 22. When the radiator fan 23 is driven, an airflow is generated from the front to the rear of the second radiator 22. A thermoswitch 25 is located in the circulation passage 30, which operates according to the temperature of the coolant flowing through the circulation passage 30. For example, the thermoswitch 25 is located in the first coolant passage 31. The thermoswitch 25 is interposed in the power supply line 26 that supplies power from the battery 27 to the radiator fan 23.

[0020] The thermoswitch 25 is turned on when the temperature of the coolant flowing through the first coolant flow path 31 exceeds a predetermined threshold value, and is turned off when the temperature of the coolant flowing through the first coolant flow path 31 becomes lower than the threshold value. Therefore, when the coolant flowing through the circulation flow path 30 becomes hot, the thermoswitch 25 is turned on and the radiator fan 23 operates, while when the coolant flowing through the circulation flow path 30 becomes cold, the thermoswitch 25 is turned off and the radiator fan 23 stops.

[0021] FIG. 3 is a left side view of each of the radiators 21 and 22 in FIG. 2 and the vicinity thereof. As shown in FIG. 3, the first radiator 21 is supported by the front frame 2d of the vehicle body frame 2 via a bracket 35. The second radiator 22 is supported by the front frame 2d via a bracket 36. The first radiator 21 is arranged so as to overlap the second radiator 22 from the front of the vehicle. The radiator fan 23 is attached to the second radiator 22 in a state adjacent to the rear side of the second radiator 22.

[0022] The radiator fan 23 includes a fan blade 23a and a fan motor 23b that drives the fan blade 23a. The radiator fan 23 is arranged to blow air toward the rear of the vehicle. By driving the radiator fan 23, an air flow that passes through the second radiator 22 from the front to the rear is generated. Since the first radiator 21 is arranged in front of the second radiator 22, air can pass through both the first radiator 21 and the second radiator 22 by driving the radiator fan 23.

[0023] There is an air gap 38 between the first radiator 21 and the second radiator 22. The air gap 38 is an air space in which no components exist. That is, the first radiator 21 directly faces the second radiator 22 without any intervening objects. In the thickness direction of the second radiator 22, the size L of the air gap 38 between the first radiator 21 and the second radiator 22 is greater than the thickness T of the second radiator 22. In the thickness direction of the second radiator 22, the size L of the air gap 38 may be greater than the thickness of the second heat exchange core 22a, which will be described later, or it may be greater than the thickness of the second tank 22b, which will be described later. When the radiator fan 23 is driven, a wide range of air passes through the second radiator 22 using the air gap 38 between the first radiator 21 and the second radiator 22.

[0024] The first radiator 21 is connected to the second radiator 22 via a second coolant tube 42. The second coolant tube 42 is connected from the rear of the first radiator 21 to the rear side of the first radiator. Specifically, the second coolant tube 42 is connected to the rear of the first tank 21b of the first radiator 21, which will be described later. In the thickness direction of the second radiator 22, the gap 38 between the first radiator 21 and the second radiator 22 is larger than the outer diameter D of the second coolant tube 42. At least a portion of the second coolant tube 42 is located in the gap 38. The second coolant tube 42 may have a portion that extends along the rear side of the first radiator 21 in the gap 38.

[0025] The height dimension of the first radiator 21 is smaller than the height dimension of the second radiator 22. The upper end of the first radiator 21 is lower than the upper end of the second radiator 22. The lower end of the first radiator 21 is higher than the lower end of the second radiator 22.

[0026] The first radiator 21 is tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end. The second radiator 22 is also tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end. For example, when viewed from the vehicle width direction, the first radiator 21 is positioned parallel to the second radiator 22. That is, the first radiator 21 and the second radiator 22 extend diagonally upward and rearward. The inclination angle of the first radiator 21 and the second radiator 22 with respect to the vertical direction is less than 45 degrees, preferably less than 30 degrees.

[0027] Furthermore, one of the first radiator 21 and the second radiator 22 may extend diagonally upward and backward, while the other radiator may extend upward at an angle closer to the vertical than the other radiator.

[0028] As shown in Figure 5A, the front cover 5 includes a front lower cowl 15, a front upper cowl 16, a front grille 17, a pair of front side cowls 18, and a front hood 19. However, the specific configuration of this front cover 5 is not limited to that described above, and various configurations can be adopted.

[0029] The front lower cowl 15 covers the front space S from the front. The headlights 14 are located on the front lower cowl 15. The front lower cowl 15 has a front grille opening 15a. The front upper cowl 16 is adjacent to the upper side of the front lower cowl 15. The front upper cowl 16 covers the front part of the front space S from above. The front upper cowl 16 has an outside air intake opening 16a.

[0030] The front grille 17 is located in the front grille opening 15a. The front grille 17 has, for example, a lattice shape and includes a plurality of outside air intake openings 17a. A front grille may also be located in the outside air intake opening 16a of the front upper cowl 16. A pair of front side cowls 18 are located above the front lower cowl 15 and on both the left and right sides of the front upper cowl 16. The front hood 19 is located behind the front upper cowl 16 and is positioned to partially overlap the front upper cowl 16 from above. When the front hood 19 is opened, the front space S is opened upward.

[0031] Returning to Figure 3, the multiple outside air intake openings 17a of the front grille 17 and the outside air intake opening 16a of the front upper cowl 16 constitute the outside air intake section 40 of the front cover 5. The outside air intake section 40 is horizontally opposed to the first radiator 21 and the second radiator 22. The front cover 5 has a sloped portion 16b that is positioned vertically above the first radiator 21 and the second radiator 22 and extends forward and downward of the vehicle. Specifically, the front upper cowl 16 has the sloped portion 16b. A shroud 50 is positioned in the front space S.

[0032] Figure 4 is a perspective view of the radiators 21, 22 and shroud 50 from the left front, as shown in Figure 3. As shown in Figures 3 and 4, the shroud 50 directs air from the outside air intake section 40 of the front cover 5 to the first radiator 21 and the second radiator 22. The shroud 50 surrounds the first radiator 21 from a direction perpendicular to the longitudinal direction of the vehicle. The shroud 50 includes an upper wall 51, a right wall 52, and a left wall 53. The upper wall 51 covers the first radiator from above. The right wall 52 covers the first radiator 21 from the right. The left wall 53 covers the first radiator 21 from the right. The air guide space enclosed by the shroud 50 is open downwards. That is, the shroud 50 does not have a lower wall.

[0033] The front end 50a of the shroud 50 is composed of the front ends of the upper wall portion 51, the right wall portion 52, and the left wall portion 53. The front end 50a of the shroud 50 is positioned to surround the entire outside air intake section 40. The front end 50a of the shroud 50 abuts against the front cover 5 around the outside air intake section 40. That is, the front end 50a of the shroud 50 abuts against the front cover 5 around the entire outside air intake opening 16a of the front upper cowl 16 and the outside air intake opening 17a of the front grille 17. Therefore, the shroud 50 collects the air flowing into the front space S from the outside air intake openings 16a and 17a and guides it toward the respective radiators 21 and 22.

[0034] Air flowing into the front space S from the outside air intake section 40 of the front cover 5 is guided by the shroud 50 and passes through the first radiator 21 and the second radiator 22. In other words, the shroud 50 facilitates the passage of air through the first radiator 21 and the second radiator 22, thereby improving the cooling performance of the first radiator 21 and the second radiator 22.

[0035] The rear end 50b of the shroud 50 is composed of the rear ends of the upper wall portion 51, the right wall portion 52, and the left wall portion 53. The rear end 50b of the shroud 50 abuts against the outer edge of the second radiator 22. The shroud 50 has a gap G between it and the first radiator 21 in a direction perpendicular to the longitudinal direction of the vehicle. Specifically, a gap G1 is formed between the upper wall portion 51 and the first radiator 21, a gap G2 is formed between the right wall portion 52 and the first radiator 21, and a gap G3 is formed between the left wall portion 53 and the first radiator 21.

[0036] Gap G1 is located above the first radiator 21. The upper wall portion 51, which faces the first radiator 21 from vertically above, extends diagonally toward the front and downward of the vehicle. However, since the upper end of the first radiator 21 is lower than the upper end of the second radiator 22, there is a gap G1 between the upper wall portion 51 and the first radiator 21. Gaps G2 and G3 are gaps located outward in the vehicle width direction of the first radiator 21.

[0037] Air flowing into the front space S from the outside air intake section 40 of the front cover 5 can reach the second radiator 22 after passing through the first radiator 21, or it can reach the second radiator 22 by passing through the gap G without passing through the first radiator 21. That is, air flowing into the front space S from the outside air intake section 40 of the front cover 5 can reach the second heat exchange core 22a of the second radiator 22 (described later) by passing through the gap G1 above the first radiator 21, or it can reach the second heat exchange core 22a of the second radiator 22 by passing through the gaps G2 and G3 on the sides of the first radiator 21.

[0038] The first radiator 21 includes a first heat exchange core 21a and a pair of first tanks 21b provided on both the left and right sides of the first heat exchange core 21a. The internal spaces of the pair of first tanks 21b are each in communication with the refrigerant flow path of the first heat exchange core 21a. One of the pair of first tanks 21b is connected to the first coolant tube 41 described above, and the other of the pair of first tanks 21b is connected to the second coolant tube 42 described above. The first coolant tube 41 may be connected to the rear side of the first tank 21b or to the side side of the first tank 21b. When air passes through the first heat exchange core 21a in the longitudinal direction of the vehicle, the coolant flowing through the first heat exchange core 21a exchanges heat with the air, and the coolant is cooled. The first tank 21b has a tapered portion 21c at its longitudinal end. In the tapered section 21c, the amount M of the first radiator 21 protruding from the first heat exchange core 21a gradually decreases as it moves outward in the longitudinal direction of the first tank 21b.

[0039] The second radiator 22 includes a second heat exchange core 22a and a pair of second tanks 22b provided on both the left and right sides of the second heat exchange core 22a. The internal spaces of the pair of second tanks 22b each communicate with the refrigerant flow path of the second heat exchange core 22a. One of the pair of second tanks 22b is connected to the second coolant tube 42 described above, and the other of the pair of second tanks 22b is connected to the third coolant tube 43 described above. The second coolant tube 42 may be connected to the front side of the second tank 22b of the second radiator 22, or to the side side of the second tank 22b. The third coolant tube 43 may be connected to the rear side of the second tank 22b, or to the side side of the second tank 22b. When air passes through the second heat exchange core 22a in the longitudinal direction of the vehicle, the coolant flowing through the second heat exchange core 22a exchanges heat with the air, and the coolant is cooled.

[0040] Figure 5A is a front view of the front of the off-road vehicle 1 shown in Figure 1, viewed from the front of the vehicle. Figure 5B is a front view of Figure 5A with the front upper cowl 16 removed. As shown in Figures 5A and 5B, in a front view of the vehicle, the first heat exchange core 21a of the first radiator 21 overlaps the second heat exchange core 22a of the second radiator 22 from the front. In a front view of the vehicle, the entire first heat exchange core 21a may overlap the second heat exchange core 22a from the front, or at least a part of the first heat exchange core 21a may overlap the second heat exchange core 22a from the front. The first radiator 21 may be smaller than the second radiator 22 in a front view of the vehicle. That is, in a front view of the vehicle, the entire first heat exchange core 21a and the pair of first tanks 21b may be smaller than the entire second heat exchange core 22a and the pair of second tanks 22b. In a front view of the vehicle, the first heat exchange core 21a may be smaller than the second heat exchange core 22a.

[0041] The upper end of the first radiator 21 is lower than the upper end of the second heat exchange core 22a of the second radiator 22, and the lower end of the first radiator 21 is higher than the lower end of the second heat exchange core 22a of the second radiator 22. Furthermore, the right end of the first radiator 21 is located inward in the left-right direction, i.e., to the left, compared to the right end of the second heat exchange core 22a of the second radiator 22, and the left end of the first radiator 21 is located inward in the right-right direction, i.e., to the right, compared to the left end of the second heat exchange core 22a of the second radiator 22.

[0042] The outer periphery of the second heat exchange core 22a protrudes from the first radiator 21 when viewed from the front of the vehicle. That is, the second heat exchange core 22a has a portion that is not hidden by the first radiator 21 when viewed from the front of the vehicle. Furthermore, because the first tank 21b of the first radiator 21 has a tapered portion 21c, the portion of the second heat exchange core 22a that is not hidden by the first radiator 21 when viewed from the front of the vehicle is increased without changing the size of the first heat exchange core 21a.

[0043] Air flowing into the front space S from the front of the vehicle through the outside air intake section 40 can pass through the first heat exchange core 21a of the first radiator 21 and then through the second heat exchange core 22a of the second radiator 22, or it can pass through the second heat exchange core 22a of the second radiator 22 without passing through the first heat exchange core 21a of the first radiator 21. In other words, the second heat exchange core 22a of the second radiator 22 can easily reach not only the air that has been heated by passing through the first heat exchange core 21a of the first radiator 21, but also the cold air that has passed outside the first radiator 21, thus improving the cooling performance of the second radiator 22.

[0044] The second heat exchange core 22a of the second radiator 22 includes a lower region R1 that protrudes downward from the first radiator 21 when viewed from the front of the vehicle, and an upper region R2 that protrudes upward from the first radiator 21 when viewed from the front of the vehicle. The lower region R1 of the second heat exchange core 22a is exposed through the outside air intake opening 17a of the front grille 17 when viewed from the front of the vehicle. As a result, air that flows in from the outside air intake opening 17a of the front grille 17, passes through the space below the first radiator 21, and flows to the rear, easily passes through the lower region R2 of the second heat exchange core 22a.

[0045] The upper region R2 of the second heat exchange core 22a is located above the outside air intake opening 16a of the front upper cowl 16 when viewed from the front of the vehicle. That is, the upper region R2 of the second heat exchange core 22a is located above the entire outside air intake opening 17a and outside air intake opening 16a, i.e., the outside air intake section 40.

[0046] Since the upper wall portion 51 of the shroud 50 extends rearward and upward, air flowing into the front space S from the outside air intake opening 16a can flow rearward and upward along the lower surface of the upper wall portion 51 of the shroud 50. Also, because the first radiator 21 is tilted rearward, when air flowing in from the outside air intake opening 16a flows along the front surface of the first radiator 21, that air tends to flow upward. Therefore, a portion of the air flowing into the front space S from the outside air intake opening 16a passes through the space above the first radiator 21 and through the lower region R1 of the second heat exchange core 22a.

[0047] As described above, the air exchanges heat with the two radiators 21 and 22, so the cooling performance of the internal combustion engine cooling system 20 can be improved without making the individual radiators 21 and 22 large in area. Also, since the two radiators 21 and 22 are arranged so that they overlap each other, the area occupied by the two radiators 21 and 22 as a whole can be reduced. Therefore, the cooling performance of the radiators 21 and 22 can be improved while preventing the off-road vehicle 1 from becoming larger.

[0048] As described above, the embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that have been modified, replaced, added, or omitted as appropriate. Furthermore, it is possible to combine the components described in the embodiments to create new embodiments. For example, some components or methods in one embodiment may be applied to other embodiments, and some components in an embodiment can be separated from other components in that embodiment and extracted as appropriate. In addition, the components described in the attached drawings and detailed description include not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology.

[0049] [Aspect] The embodiments described above are specific examples of the following embodiments.

[0050] (Aspect 1) The cabin with the crew seats, A front cover that covers the front space located in front of the cabin and includes at least one outside air intake opening facing forward of the vehicle, Internal combustion engines and A circulation passage through which a coolant flows to cool the internal combustion engine, In the aforementioned front space, a first radiator is positioned behind the outside air intake opening, interposed in the circulation channel, and includes a first heat exchange core. The system comprises a second radiator located behind the first radiator in the front space, interposed in the circulation path, and including a second heat exchange core, The first radiator is an off-road vehicle in which the first heat exchange core is positioned so as to overlap the second heat exchange core from the front.

[0051] With this configuration, air exchanges heat with the two radiators, allowing for improved cooling performance without requiring large surface areas for each individual radiator. Furthermore, since the two radiators are positioned to overlap, the total area occupied by the two radiators combined can be reduced. Therefore, it is possible to improve the cooling performance of the radiators while preventing an increase in vehicle size.

[0052] (Aspect 2) The off-road vehicle according to embodiment 1, wherein the first radiator is located upstream of the second radiator in the circulation path.

[0053] With this configuration, the two radiators are arranged in series in the circulation path, which simplifies the piping of the circulation path and allows for gradual cooling of the coolant flowing through the circulation path. Furthermore, since the first radiator is positioned in front of the second radiator and upstream of the second radiator in the circulation path, the temperature difference between the air and the coolant is increased in the first radiator, allowing for effective cooling of the coolant, and the coolant can be further cooled in the second radiator.

[0054] (Aspect 3) The off-road vehicle according to embodiment 1 or 2, wherein the first radiator is smaller than the second radiator when viewed from the front of the vehicle.

[0055] With this configuration, not only the air that has passed through the first radiator and been heated, but also the air that has not passed through the first radiator can easily reach the second radiator, thereby improving the cooling performance of the second radiator.

[0056] (Aspect 4) The off-road vehicle according to embodiment 3, wherein the first radiator is arranged such that the upper end of the first radiator is lower than the upper end of the second heat exchange core, and the lower end of the first radiator is higher than the lower end of the second heat exchange core.

[0057] With this configuration, air passing above and below the first radiator can reach the second heat exchange core of the second radiator, thereby improving the cooling performance of the second radiator.

[0058] (Aspect 5) The system further comprises a radiator fan located behind the second radiator, An off-road vehicle according to any one of embodiments 1 to 4, wherein the gap between the first radiator and the second radiator is greater than the thickness of the second radiator in the thickness direction of the second radiator.

[0059] With this configuration, when the radiator fan is running, the air gap between the first and second radiators can be used to allow a wide range of air to pass through to the second radiator, thereby improving the cooling performance of the second radiator.

[0060] (Aspect 6) The circulation path includes a coolant tube connecting the first radiator to the second radiator. An off-road vehicle according to any one of embodiments 1 to 5, wherein the gap between the first radiator and the second radiator is larger than the outer diameter of the coolant tube in the thickness direction of the second radiator.

[0061] This configuration allows the coolant tubes to be connected to the rear side of the first radiator, improving the flexibility of the coolant tube placement.

[0062] (Aspect 7) The front cover is fitted vertically upward to the first radiator and the second radiator and has a slope portion that extends forward and downward to the front of the vehicle. An off-road vehicle according to any one of embodiments 1 to 6, wherein the first radiator is positioned such that the upper end of the first radiator is lower than the upper end of the second radiator.

[0063] This configuration allows the first and second radiators to be positioned closer to the sloped portion of the front cover in the vertical direction, thereby improving the efficiency of component layout in the front space.

[0064] (Pattern 8) An off-road vehicle according to any one of embodiments 1 to 7, wherein at least one of the first radiator and the second radiator is tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end.

[0065] This configuration allows at least one of the first and second radiators to be more compact in the vertical direction, improving the efficiency of component layout in the front space.

[0066] (Aspect 9) The first radiator is tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end. The second heat exchange core includes a lower region that protrudes downward from the first radiator in a front view of the vehicle, and an upper region that protrudes upward from the first radiator in a front view of the vehicle. The lower region of the second heat exchange core is exposed through the at least one outside air intake opening in a front view of the vehicle. The off-road vehicle according to embodiment 8, wherein the upper region of the second heat exchange core is located above the entirety of the at least one outside air intake opening in a front view of the vehicle.

[0067] With this configuration, the lower region of the second heat exchange core is exposed through the outside air intake opening when viewed from the front of the vehicle. Therefore, air flowing in from the outside air intake opening and then flowing rearward under the first radiator easily passes through the lower region of the second heat exchange core. Also, because the first radiator is tilted backward, when air flowing in from the outside air intake opening flows along the front of the first radiator, it tends to flow upward rather than downward, making it easier to reach the upper region of the second heat exchange core. Thus, the cooling performance of the second radiator can be improved while maintaining good cooling performance for the first radiator.

[0068] (Aspect 10) The front space is further provided with a shroud that directs outside air from at least one outside air intake opening to the second radiator, The off-road vehicle according to any one of embodiments 1 to 9, wherein the shroud surrounds the first radiator from a direction perpendicular to the longitudinal direction of the vehicle.

[0069] This configuration allows air flowing into the front space through the air intake opening in the front cover to pass through the first and second radiators, thereby improving the cooling performance of each radiator.

[0070] (Aspect 11) The off-road vehicle according to embodiment 10, wherein the shroud has a gap between it and the first radiator in a direction perpendicular to the longitudinal direction of the vehicle.

[0071] With this configuration, air flowing into the front space through the outside air intake opening of the front cover can pass through the first radiator before reaching the second radiator, or it can reach the second radiator without passing through the first radiator. Therefore, a good balance can be maintained between the cooling performance of the first and second radiators.

[0072] (Aspect 12) The off-road vehicle according to embodiment 11, wherein the gap between the shroud and the first radiator includes a gap located outward in the vehicle width direction of the first radiator.

[0073] With this configuration, air flowing into the front space through the outside air intake opening of the front cover can pass through the gap on the side of the first radiator and reach the second radiator. Therefore, the cooling performance of the second radiator can be enhanced by using the outer portion of the second radiator in the vehicle width direction.

[0074] (Aspect 13) The off-road vehicle according to embodiment 11 or 12, wherein the gap between the shroud and the first radiator includes a gap located above the first radiator.

[0075] With this configuration, air flowing into the front space through the air intake opening in the front cover can pass through the gap above the first radiator and reach the second radiator. Therefore, the upper part of the second radiator can be used to improve its cooling performance.

[0076] (Aspect 14) The aforementioned at least one outside air intake opening includes a plurality of outside air intake openings, The off-road vehicle according to embodiment 10 or 11, wherein the shroud is positioned such that, in a front view of the vehicle, the front end of the shroud surrounds the entirety of the plurality of outside air intake openings.

[0077] This configuration allows air flowing into the front space from multiple outside air intake openings to be collected and directed towards each radiator.

[0078] (Aspect 15) The off-road vehicle according to embodiment 14, wherein the front end of the shroud abuts against the front cover around the entire perimeter of the plurality of outside air intake openings.

[0079] This configuration allows air flowing into the front space through the outside air intake opening to be stably guided into the airflow space of the shroud.

[0080] (Aspect 16) The shroud includes an upper wall portion that covers the first radiator from above, a right wall portion that covers the first radiator from the right, and a left wall portion that covers the first radiator from the left. The off-road vehicle according to any one of embodiments 10 to 15, wherein the air intake space enclosed by the shroud is open to the bottom.

[0081] This configuration allows for easy placement of a structure that supports the first radiator from below without interfering with the shroud. [Explanation of symbols]

[0082] 1. Off-road vehicle 2. Vehicle frame 5 Front cover 6 passenger seats 12 Internal Combustion Engines 16 Front Upper Cowl 16a Opening for outside air intake 16b Slope section 17 Front Grille 17a Opening for outside air intake 20 Internal Combustion Engine Cooling System 21. Radiator No. 1 21a First heat exchange core 22. Second radiator 22a Second heat exchange core 23 Radiator fan 24 Coolant pump 30 Circulation channels 38 void 42 Coolant tubes 50 Shroud 50a front end 51 Upper wall 52 Right wall section 53 Left wall section C Cabin G, G1, G2, G3 gaps R1 Lower area R2 upper area S Front Space T Thickness of the second radiator

Claims

1. The cabin with the crew seats, A front cover that covers the front space located in front of the cabin and includes at least one outside air intake opening facing the front of the vehicle, Internal combustion engines and A circulation passage through which a coolant flows to cool the internal combustion engine, In the aforementioned front space, a first radiator is positioned behind the outside air intake opening, interposed in the circulation channel, and includes a first heat exchange core. The system comprises a second radiator located behind the first radiator in the front space, interposed in the circulation path, and including a second heat exchange core, The first radiator is an off-road vehicle in which the first heat exchange core is positioned so as to overlap the second heat exchange core from the front.

2. The off-road vehicle according to claim 1, wherein the first radiator is located upstream of the second radiator in the circulation path.

3. The off-road vehicle according to claim 1, wherein the first radiator is smaller than the second radiator when viewed from the front of the vehicle.

4. The off-road vehicle according to claim 3, wherein the first radiator is arranged such that the upper end of the first radiator is lower than the upper end of the second heat exchange core, and the lower end of the first radiator is higher than the lower end of the second heat exchange core.

5. The system further comprises a radiator fan located behind the second radiator, The off-road vehicle according to claim 1, wherein the gap between the first radiator and the second radiator is greater than the thickness of the second radiator in the thickness direction of the second radiator.

6. The circulation path includes a coolant tube connecting the first radiator to the second radiator. The off-road vehicle according to claim 1, wherein the gap between the first radiator and the second radiator is larger than the outer diameter of the coolant tube in the thickness direction of the second radiator.

7. The front cover is positioned vertically above the first radiator and the second radiator and has a slope portion that extends forward and downward of the vehicle. The off-road vehicle according to claim 1, wherein the first radiator is positioned such that the upper end of the first radiator is lower than the upper end of the second radiator.

8. The off-road vehicle according to claim 1, wherein at least one of the first radiator and the second radiator is tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end.

9. The first radiator is tilted backward with respect to the vertical direction such that its upper end is located further rearward than its lower end. The second heat exchange core includes a lower region that protrudes downward from the first radiator in a front view of the vehicle, and an upper region that protrudes upward from the first radiator in a front view of the vehicle. The lower region of the second heat exchange core is exposed through the at least one outside air intake opening when viewed from the front of the vehicle. The off-road vehicle according to claim 8, wherein the upper region of the second heat exchange core is located above the entirety of the at least one outside air intake opening in a front view of the vehicle.

10. The system further comprises a shroud positioned in the front space, which guides outside air from at least one outside air intake opening to the second radiator, The off-road vehicle according to claim 1, wherein the shroud surrounds the first radiator from a direction perpendicular to the front-rear direction of the vehicle.

11. The off-road vehicle according to claim 10, wherein the shroud has a gap between it and the first radiator in a direction perpendicular to the longitudinal direction of the vehicle.

12. The off-road vehicle according to claim 11, wherein the gap between the shroud and the first radiator includes a gap located outward in the vehicle width direction of the first radiator.

13. The off-road vehicle according to claim 11, wherein the gap between the shroud and the first radiator includes a gap located above the first radiator.

14. The aforementioned at least one outside air intake opening includes a plurality of outside air intake openings, The off-road vehicle according to claim 10, wherein the shroud is positioned such that, in a front view of the vehicle, the front end of the shroud surrounds the entirety of the plurality of outside air intake openings.

15. The off-road vehicle according to claim 14, wherein the front end of the shroud abuts against the front cover around the entire perimeter of the plurality of outside air intake openings.

16. The shroud includes an upper wall portion that covers the first radiator from above, a right wall portion that covers the first radiator from the right, and a left wall portion that covers the first radiator from the left. The off-road vehicle according to claim 10, wherein the air intake space enclosed by the shroud is open downwards.

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